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By Abel Jaime & Isauro Sanchez

Engineering 201

(Date)

The Materials of a Euro coin

In the early 2002, Europe wanted to make its currency more accessible across Europe.

They, therefore, needed to choose a currency that was easy to mint. More importantly, the

currency had to be soft and ductile enough to make stamping easy. In addition, to avoid wear and

tear, it had to be strong and hard. For health purposes, the currency’s surface had to be

antibacterial. As a result, infectious pathogens could not thrive on the surface. Consequently, the

Euro was created to satiate these needs. Interestingly, the Euro was to be made of coppers since

copper could meet all the desired characteristics. Furthermore, it is abundantly available and

cheap.

Nonetheless, the Euro is made from recycled copper from a scrap yard. The copper from

scrap yard is melted at 1200 degrees Celsius. Then, it is chopped into large metal portions after

cooling down. At 900 degrees Celsius, the large metal portions are further processed through a

process called hot rolling. Hot rolling involves rolling the metal portions until they are flat and

thin enough for the coins to be stamped out. In this process, two rolls are used to make the metals

thin, since rolling a hot metal between two rolls reduces the metal thickness, as a result of the

compressive stresses of the rolls. At this point, a forming operation called hot working occurs.

However, to strengthen back the coin, cold-working process is used. Coining is a cold working

process that plastically deforms the work-piece so that stamping can be precise. Thus, each coin

is compressed in between a copper and nickel, at a ratio of seventy-five weight percent copper

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and twenty-five weight percent nickel. At this point, the copper is stamped onto the nickel,

creating a sandwich-like feature of copper-nickel-copper sandwich.

As a fact, having a copper base for a Euro shows how secure it is. The validity of a Euro

is measured in various ways. For instance, the weight of Euro coins makes it applicable in a

vending machine. Upon entering a vending machine, each coin is weighted to determine its

value; the weights of the coins vary from one denomination to the other, such that a 1-euro, 2-

euro, and a 20-euro cent weigh differently. Another test of the validity of the Euro is determining

how magnetic a coin is. Each coin has a different magnetic field. Therefore, vending machines

that sell drinks, crisp, chocolate, among others, use this characteristic to determine if the right

coin has been inserted. Additionally, a Euro can be tested by measuring its electrical resistance.

The coin’s material composition is designed to have the right electrical resistance

(resources.schoolscience.co.uk). The 2-euro coin has its magnetic properties by its hole due to its

copper-nickel weight percent. In particular, copper and Nickel were selected because they are

inexpensive compared to other materials.

When developing the 2-euro coin, many people feared that bacteria would spread.

However, “Bacteria do not survive on copper and, since copper is a non-allergenic material,

people cannot contract a rash from handling them.” (resources.schoolscience.co.uk/)

The average life span of a euro coin before it starts to wear out is 30 years. Although 30

years seems a short time, it is longer than the lifespan of a dollar bill, which is only about 18

years. The reason its lifespan is 30 years before it becomes worn out is fatigued within the time,

for example, if the same coin is dropped into a vending machine repeatedly, eventually the

machine is not able to read it because of wearing out or deformation. Nonetheless, the copper

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corrosion makes it possible for the coin to look new over the years. The expected lifespan gives

vital information, so newer coins are introduced to replace the ones that are expected to wear out.

In conclusion, the science behind a 2-Euro coin is not complicated. Copper and Nickel

were chosen because they are relatively cheap compared to other material. The metals are

recycled once they are worn out, reducing environmental pollution. Two processes, including

Hot and Cold-working, and possibly rolling are used to make the 2-Euro Coin. The possible

equations that could be used are the following, Cold working ([Ao-Ad]/Ao) *100 since coining

is a cold working process.

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FIGURE A

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Diagram 1: Euro coin processing

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Works Cited

Callister, William D., and David G. Rethwisch. Fundamentals of Materials Science and

Engineering: An Integrated Approach. Hoboken, NJ: Wiley, 2012. Print.

"How Its Made - The 2 Euro Coin (â¬2)." � YouTube. YouTube, n.d. Web. 16 Apr. 2015.

https://www.youtube.com/watch?v=rFDsSMDeV3w

"2 Euro Coin." Wikipedia. Wikimedia Foundation, n.d. Web. 16 Apr. 2015.

http://en.wikipedia.org/wiki/2_euro_coin